. >> mississippi was the first to report high flu activity in november. just six weeks later, 29 states did. adding to the misery, manufacturers of tam a flu used to treat sick children and flu zone, a widely used vaccine say supplies were running low or completely gone. this season's flu bug is also particularly potent, responsible for severe outbreaks in years past. >> there's something about the way the virus affects us that causes more disease and more inflammation. >> reporter: at massachusetts general hospital, the emergency room is packed, and beds are full. how would you rate this season? >> this is certainly among the worst flu seasons that we've had and it's really pushing us to our breaking point. >> reporter: the vaccine can lessen the severities in addition to keeping others from getting sick. >> it's called the concept of herd immunity. so if almost everybody is immune to the virus, then that virus has a very difficult time of going through the population and making vulnerable people in that population sick. >> reporter: to give you an idea